gmail-smtp-in.l.google.com[2a00:1450:400c:c09::1b] said: 550-5.7.1
[2001:41d0:a:5ea::1] The IP address sending this message does not have
550-5.7.1 a PTR record setup. As a policy, Gmail does not accept messages
from 550-5.7.1 IPs with missing PTR records. Please visit 550-5.7.1https://support.google.com/mail/answ...authentication for more 550
5.7.1 information. k74si739962wmc.97 - gsmtp (in reply to end of DATA
command)